From e0e7f0fa4a487758b2d51f9e8b0ab7640d1d49bb Mon Sep 17 00:00:00 2001
From: Rob Rix <rob.rix@github.com>
Date: Tue, 24 May 2016 13:04:10 -0400
Subject: [PATCH] Add a toPrettyDiff function to abstract the construction of
 pretty diffs away.

---
 test/AlignmentSpec.hs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/test/AlignmentSpec.hs b/test/AlignmentSpec.hs
index 981647b86..114bae486 100644
--- a/test/AlignmentSpec.hs
+++ b/test/AlignmentSpec.hs
@@ -218,6 +218,11 @@ toAlignedChildren = join . (`evalState` both 0 0) . mapM go
           put $ (+) <$> prev <*> modifyJoin (fromThese 0 0) (length <$> contents)
           return []
 
+toPrettyDiff :: [BranchElement] -> PrettyDiff [(String, Range)]
+toPrettyDiff elements = PrettyDiff sources (alignBranch id children ranges)
+  where (sources, ranges) = toSourcesAndRanges elements
+        children = toAlignedChildren elements
+
 instance Arbitrary BranchElement where
   arbitrary = oneof [ key >>= \ key -> Child key <$> joinTheseOf (contents key)
                     , Margin <$> joinTheseOf margin ]